(a) Field of the Invention
This invention relates to a seed dispensing device.
(B) Description of the Prior Art
In our British Pat. No. 1450677, we have described a seed dispensing device which may form part of a seed drill and which is arranged to dispense seeds one at a time at regular, predetermined intervals. In its broadest aspect, that seed dispensing device comprises a housing defining a reservoir for seeds, inlet means which in use enable seeds to be fed into the reservoir there to form a mass of seeds, a wheel member mounted in a substantially vertical plane for rotation in at least one direction within the housing and having a number of spoke-like projections thereon, a cup capable of loosely holding a seed mounted on each such projection adjacent the periphery of the wheel and so oriented that it opens tangentially and forwardly in said direction of rotation of the wheel, thus upon rotation thereof through the mass of seeds permitting said cups as they pass therethrough to pick up seeds, brushes arranged within the housing beyond the reservoir in said direction of rotation which brush against the cups and aid retention of seeds therein as each cup is rotated past the top dead center position, and outlet means situated in the housing outside the periphery of the wheel member beyond said brushes in the direction of rotation for receiving seeds discharged from said cups under centrifugal and gravitational forces and dispensing the same. Such a seed dispenser is referred to hereinafter as our "seed dispensing device of the kind described."
Though our seed dispensing device of the kind described in general functions well, we have found nevertheless that the delivery of seeds may in certain circumstances not be perfectly regular. For instance, occasionally two seeds may be delivered at once, or no seed may be delivered when one would be expected. These defects may be attributed to one or more causes, such as a cup picking up two seeds rather than one, or a cup picking up foreign matter rather than a seed and delivering that foreign matter to the outlet means.